Forensic Science - Physical Evidence

When evidence can be associated only with a group and never a single source, that evidence is said to possess:

• Class categories

• Class characteristics

• Group categories

• Group characteristics

The examination of physical evidence by a forensic scientist is usually undertaken for:

• Identification or comparison purposes

• Proving a suspect's guilt in the courtroom

• Proving a suspect's innocence in the courtroom

• Assisting law enforcement in the apprehension of an offender

Properties of evidence that can be attributed to a common source with an extremely high degree of certainty is/are:

• Comparison characteristics

• Referent characteristics

• Class characteristics

• Individual characteristics

Most items of physical evidence retrieved at crime scene:

• Can be definitively linked to a single person or object

• Can be used in court with little challenge to their scientific validity

• Can be manipulated by forensic scientists to "tell" the story they wish to tell

• Cannot be definitively linked to a single person or object

The weight or significance of physical evidence in a courtroom is left to the ______ to determine.

• expert witnesses or criminalists who are testifying

• laboratory analysts who are interpreting the results of their tests

• the trier of facts, usually a jury of laypeople (amateurs)

• the prosecutor, who instructs the jury of how much weight to assign to a piece of evidence

True or False: Physical evidence is usually examined by a forensic scientist to determine the identity of the offender of the crime.

• True

• False

True or False: Technology surrounding the forensic sciences has evolved to the point that an examiner can assign approximate probability values to the comparison of most class physical evidence.

• True

• False

True or False: Generally speaking, the chance of an investigator finding physical evidence possessing individual characteristics is far greater than finding class physical evidence.

• True

• False

True or False: a database applicable to DNA profiling is CODIS.

• True

• False

What is the purpose of identification?